Achieving low contact resistance through copper-intercalated bilayer MoS$_2$

TL;DR

This paper presents a theoretical design of a MoS₂-based transistor with copper-intercalated electrodes that achieves near-quantum-limit low contact resistance, enabling lower voltage operation and improved device performance.

Contribution

It introduces a novel copper-intercalation method to significantly reduce contact resistance in bilayer MoS₂ transistors, surpassing previous limitations.

Findings

Contact resistance near 16.7 Ω·μm (zigzag) and 30.0 Ω·μm (armchair) at 0.6 V.

Elimination of tunneling barrier and formation of ohmic contacts.

Lower operating voltages due to small contact potential difference.

Abstract

The high contact resistance between MoS$_2$ and metals hinders its potential as an ideal solution for overcoming the short channel effect in silicon-based FETs at sub-3nm scales. We theoretically designed a MoS$_2$-based transistor, featuring bilayer MoS$_2$ connected to Cu-intercalated bilayer MoS$_2$ electrodes. At 0.6 V, contact resistance is 16.7 $\Omega \cdot \mu$m (zigzag) and 30.0 $\Omega \cdot \mu$m (armchair), nearing or even surpassing the 30 $\Omega \cdot \mu$m quantum limit for single-layer materials. This low resistance is attributed to the elimination of the tunneling barrier and the creation of ohmic contacts. Additionally, the small contact potential difference enables lower operating voltages. Our intercalation design offers a novel approach to achieving low contact resistance in 2D electronic devices.